Here's how to replace a mailbox post in concrete in just a few steps in accordance with USPS guidelines.
Time 2 - 3 hours plus drying time
ComplexityIntermediate
Cost$40-$60
Introduction
Learn how to replace a mailbox post with this simple step-by-step project. Perfect for DIY enthusiasts looking to upgrade their curb appeal.
Tools Required
- Auger drill bit
- Bucket
- Drill
- Hammer drill
- Hi lift jack
- Jig Saw
- Level
- Mallet
- Post and pipe level
- Post hole digger
- Shovel
- Tape measure
- Tarp
- Tow chain
- Work gloves
Materials Required
- Concrete form tube
- Fast setting concrete
- Gravel
- Mailbox post
- Rebar
- Rope
- Stakes
Is your mailbox wobbling every time you touch it? Or are you looking to add a bit of curb appeal flair? Replacing a mailbox post may seem like a big task, but it’s easier than you might think. You’ll need a rain-free day, a new mailbox post, and a few tools.
You will likely need to remove a mailbox post set in concrete, which will require some labor. While removing the steel mailbox post, I encountered an unexpected issue. The post broke from the cement block due to rust as the hi-lift jack raised it from the ground. I had to manually dig around the mailbox concrete to wrap the chain around it securely to raise it out. Although this method worked fine, it cost me extra time and gave me quite the arm workout.
One crucial aspect of this project is the specific guidelines for installing a mailbox post. The USPS website provides all the details to ensure compliance with location requirements, such as the distance the post needs to be from the curb.
Since you’re already replacing your mailbox post, this might be a good time to consider installing a new mailbox. Confirm that the new mailbox will fit the new post if you decide to do this. Online photos can sometimes be misleading and not show the true size of the item, so it’s important to take accurate measurements.
When to call a pro
You typically don’t need a professional to install a new mailbox post. It’s a relatively straightforward DIY project that most homeowners can handle with basic tools and materials. However, hiring a professional might be a good option if you’re uncomfortable using these tools or materials or have physical limitations. When doing this project, one absolute must is to contact your local utility experts to mark any utilities in your yard.
Project step-by-step (10)
Step 1
Remove the mailbox
Use a drill to remove the screws that are securing the mailbox to the post and remove it.
Step 2
Remove the old mailbox post
Attach one end of the tow chain to the bottom of the mailbox post. Then, connect the other end of the tow chain to a hi-lift farm jack. Place the jack about a foot away from the post, start cranking the handle, and use your other hand to stabilize the jack. Once the post is primarily out of the ground, you can finish pulling it out manually. If the post breaks from the concrete, you can wrap the tow chain around the concrete and repeat the process.
Step 3
Review USPS guidelines
The USPS guidelines for installing a mailbox post are to bury the post no more than 24-inches deep and ensure that the bottom of the mailbox sits 41 to 45 inches off the road’s surface. The mailbox needs to be six to eight inches away from the curb. Use a tape measure to ensure you are in the correct location before digging.
Step 4
Dig mailbox post hole
To dig a hole for the post, you will need a drill bit auger connected to a hammer drill or mud mixer and a post hole digger. You can get away without using an auger, but it speeds up the process and saves your arms. Ensure that the auger is fully rotating before penetrating the ground. Keep the hammer drill close to your body to maintain control while breaking up the ground. Remove the dirt using a post-hole digger or shovel. Remember to take breaks while digging to check the hole depth with a tape measure to ensure that the concrete form tube will fit properly and that you are not digging too deeply. Consider that the gravel layer you will place at the bottom of the hole will be four to six inches deep. Then, place the concrete form tube into the hole to verify that the diameter fits.
TIP: Use a tarp at the dig site as a place to discard the dirt you dig out of the hole. It will make it a lot easier to clean up at the end.
Step 5
Lay down gravel
When you have reached your desired depth, lay four to six inches of pea gravel into the post hole and level it by hand.
Adjust the mailbox’s height as necessary using a tape measure for accuracy. When attached to the post, the bottom of the mailbox needs to be 41 to 45 inches off the road’s surface. Add or remove gravel to make the necessary height adjustments. Once secured to the post, double-check that the mailbox will be positioned six to eight inches away from the curb.
Step 6
Measure and cut the concrete form tube
Place the concrete tube in the hole and mark two inches from the surface height with a tape measure. With a jigsaw, cut the concrete form tube a couple of inches shorter than the ground surface. Once cut, position the cut form tube into the hole and fill dirt around the outside of the tube so it fits snugly.
Step 7
Secure the post
Place the mailbox post exactly where you’d like it. Attach a pipe level and secure it with stakes and rope to keep it plumb and prevent movement while pouring the concrete.
TIP: If you install a wooden mailbox post, you can secure it with a couple of 2x4s to keep it level.
Step 8
Pour the concrete
Fill the concrete form tube halfway with fast-setting concrete mix, add the required water and mix it with a metal rod. After thoroughly mixing, fill the rest of the form tube with concrete until it reaches the top, then repeat the mixing process. Check that the post is plumb and adjust it as needed by wiggling and changing its position. Once the concrete sets, you won’t be able to adjust the post again, so take the time to ensure it’s level. Give the concrete 12-24 hours to cure before removing the supporting stakes.
Step 9
Remove post supports
Once the concrete has cured, remove the post supports and install the mailbox onto the post.
Step 10
FAQ
How wide should a mailbox post hole be?
The diameter of the post hole should be two to three times the width of your post. For example, if you have a three-inch post, the hole should be six to nine inches in diameter.
How much concrete do I need for a mailbox post?
A 3-inch post in a 24-inch deep by 9-inch diameter hole will require three 50-lb bags of fast-setting concrete. A 4-inch post in a 24-inch deep by 12-inch diameter hole will require four 50-lb bags. The amount of concrete needed for a mailbox post depends on its diameter and the hole size.
What kind of concrete do you use for a mailbox?
Fast-setting concrete mix is a good option because it sets quickly and is strong enough to support a mailbox. However, even though it’s advertised to dry in 20-40 minutes, it takes 12-24 hours to cure enough to keep the post from moving.
Originally Published: August 30, 2024
